It’s not a shark! It’s the fin of a Mola mola, or ocean sunfish. One of our staff members spotted this huge fish in mid-August, just off Little Mark Island near Bailey Island, Harpswell. He shared a photo of it with our Water Reporter network. Since then, we have spotted several more of these disk-shaped fish in our local waters. Sunfish are found in tropical and temperate waters, often in deeper water than Casco Bay.
Its common name of ocean sunfish comes from the creature’s habit of lying on its side at the surface, possibly waiting for seabirds to nibble on its array of parasites. Or it may be warming in the sun after a deep dive in search of jellyfish and other gelatinous creatures. One of the aspects that makes it endearing is that its big eyes and O-shaped mouth make it appear to be in a perpetual state of surprise.
Its scientific name, Mola, is Latin for millstone — a large round stone used to grind grain. It also describes this fish’s shape, which can reach 6 to 10 feet across.
We welcome all sorts of reports of what you are seeing around Casco Bay, good and bad. Many Water Reporters use hashtags to organize their observations. To see a map of all the #wildlife posts shared with our group, click here.
Mount Desert Islander posted this story about the Mola mola just yesterday, if you want to read more.